Seam locator for casing perforators



Sept. 29, 1931.- R. Moss A SEAM LOCA'IOR FOR CASING PERFORATORS Filed Nov. 12, 1929 //v Me/v Toe: B05605 Moss Patented Sept. 29, 1931 UNITED STATES PATENT OFFICE ROSCOE MOSS, OF LOS ANGELES, CALIFORNIA, .ASSIGNOR T ROSCOE MOSS COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA SEAM LOCATOR FOR CASING PERFORATORS Application filed November 12, 1829. Serial No. 406,642.

This invention relates to perforators of the general character em loyed for perforating casing within a we 1 and relates particularly to a perforator having a seam locator and further relates to a seam locator which may be attached to various types of perforators.

It is customary to line wells, especially those from which water is to be obtained, with stove-pipe casing, so termed for the reason that it is made after the manner of making stove-pipe by rolling u sheet'metal to tubular form. The sheets rom which this stovepipe casing is made have their longitudinal edges overlapping so as to form lap-seams, which seams may be secured by rivets, spot Welding, or line welding.

It is an object of my invention to provide a perforator for easing of the'above and other characters having a device thereon whereby a vertical seam in the casing may be located after theperforator has been lowered into the well to a desired position, thus mak-.

, ing it possible to locate a casin seam and to avoid such seam during the perforating operation so that there will be no. possibility of the seam being opened by the perforator and the strength of the casing thereby impaired.

A further object of the invention is to provide a perforator having a frame equipped with means for suspending the frame within the well and having means for rotating the I frame while in place within the casing in '55 order to cause the seam locator of the perforator to circularly traverse the inner surface of the casing. V

A further object of the invention is to pro,- vide a seam locator, as an article of manufacture, which may be readily attached to a casing perforator and having therewith means for securing it to a perforator with which its use is desired.

A further object of the invention is to provide a seam locator of this character including an engager bar and means for yieldably forcing the engager bar outwardly into engagement with the inner surface of a casing, the outer end of the engager being sloped off in such a manner that a sharp shoulder is formed which will engage and be stopped by a scam when moved in a direction in opposition to said seam, but the outer end being so formed that it will ride over horizontal seams during the raising and lowering of the perforator within the casing.

Further objects and advantages of the invention will be made evident from the following part of the specification.

Referring to the drawings which is for illustrative purposes only,

Fig. l is a vertical sectional view showing a perforator equipped with a seam locator in operative position within a well casing.

Fig. 2 is an enlarged cross section on a plane represented by the line 22 of Fig. 1, thisfigure showing a plan view of the perforator and the seam locator thereof.

Fig. 3 is an enlarged partly sectioned detail taken on a plane indicated by 3-3 of Fig. 2 and showing the spring means which I employ for yieldably holding the engager of the seam locator in extended position.

Fig. 4 is a fragmentary cross section on a plane represented by the line 44 of Fig. 2.

In the simple embodiment of my invention shown in the drawings 11 indicates a perforator which has been lowered into a casing 12 for the purpose of cutting holes in the casing for admission of fluid from the earth structure into the interior of the casing. The perforator 11 consists of a frame 13 including a curved plate 14, a cutter supporting bar 15, links 16 for supporting the cutter bar in a desired spaced and vertically swingable relationship to the plate 14, and brackets 17 to which the inner ends of the links 16 are hinged by means of pivots 18, there being hinge pins 19 at the outer ends of the links 16 for joining the outer ends of the links with the upper and lower ends of the cutter bar 15. Upward and downward movement of the links 16 is limited by stops 17a on the brackets 17. A bracket 21 extending radially inwardly from the upper end of the plate 14, by means of across pin 22, supports a suspension clevis 23 to which a rope 24 may be attached, as shown in Fig. 1, whereby to suspend the frame 13 of the perforator 11 at a the line desired position within the casing 12. By means of a pivot 26 situated intermediate the ends of the cutter bar 15, a perforating tool 27 is hinged, this perforating tool including a lever arm 28 to which a pull rod 29 is pivotally secured, as indicated at 30. lVhen the pull rod is pulled upwardly for the purpose of accomplishing a perforating operation, the perforating tool first swings on the pivot 26 in clockwise direction, bringing the cutting point 32 thereof into engagement with the wall of the casing 12. As the upward force exerted by the pull rod 29 continues the clockwise rotation of the perforating tool 27, the cutting point or end 32 is forced outwardly through the metal wall of the casing 12, the entire perforating tool 27 swinging in upward direction about the point or end 32 thereof toward the position indicated by dotted lines 31, carrying upwardly with it the cutter bar 15 so that when a perforating operation is completed the cutter bar and the links 16 will reside in the positions thereof indicated by dotted lines 35. In a position above and in substantial alignment with the perforating tool 27, a seam locator 37 is mounted, this seam locator being preferably of such simple form that it may be cheaply manufactured and economically incorporated in the perforator structure. Although the seam locator may be made in various other manners, I prefer to employ an engager bar 38 of cylindrical form which may be received in a tubular guide member 39, which guide member in turn is equipped with a base plate 40 whereby it may be secured by means of bolts 41 to a U-shaped frame 12 which extendsin lateral direction from the inner face of the curved plate 1 1. lVithin the inner end of the tubular guide member 39, as shown best in Fig. 3, a compression spring l4 functions to exert a resilient outward force against the inner end 45 of the engager bar 38 whereby to yieldably force the engager bar in outward direction, the outward movement of the engager bar 38 being limited by a vertical pin 16 which extends through a vertical and longit-udinal slot 17 in the engager. In addition to limiting the inward and outward movement of the engager 38, the pin 46 prevents rotation of the engager 38 in the guide member 39.

As shown in Figs. 2 and 3, the engager 38 is provided with an engaging point or shoulder 49, and the end of the engager 38 is sloped back from the engaging point or shoulder 19 in three directions, first. rearwardly as indicated at 51 in Fig. 2, and then upwardly and downwardly as indicated respectively by the numerals 52 and 53 of Fig. 3. lVith the end of the engager so formed, it is evident that the engagcr will ride over projections such as seams of a casing when moved upwardly or downwardly or rear-wardly, as indicated by the arrow 5% of Fig. 2, but the engager will stop against any relatively abrupt projection which it may engage when being moved in a direction opposite to that indicated by the arrow 54 of Fig. 2.

In Fig. 2 the casing 12 is clearly shown as consisting of an inner metal tube 56 and an outer metal tube 57, the inner vertical edge 58 of the plate or sheet of metal forming the tube 56 overlapping the outer vertical edge 59. The vertical edges of the sheet of metal forming the outer tube 57 overlap, as indicated at 61, in a position adjacent to the outer edge portion 59 of the inner tube 56. In its use the perforator is lowered by means of rope 2st to a desired position within the easing 12. By means of the pull bar 29 the perforator is then rotated in clockwise direction, as indicated by the arrow of Fig. 2, the perforator swinging during such rotation from the position indicated by dotted lines (36 in Fig. 2 toward the position in which it is shown in full lines in such figure. Furthermore, the engager 38 is, during such rotation, sliding along the inner face of the casing due to the fact that it is resiliently held in outward direction by the spring 44.. The rotation of the perforator 11, as previously described, results in the movement of the engager 38 from its. position shown in dotted lines (38 toward and in opposition to the shoulder 69 formed by the seam of the casing 12. Upon the engaging point 19 of the engager 38 reaching the shoulder 69, further rotation of the perforator will be resisted, which fact will inform the operator that the perforating tool 27 is in alignment with a seam of the casing 12. The operator then rotates the perforator in reverse direction, such as indicated by the arrow a l of Fig. 2, so as to remove the perforator a short distance from its position of alignment with the casing seam. The perforating tool 27 is then operated in the manner previously described, the perforator 11 then being intermittently moved in anti-clockwise direction through consecutive positions of perforation, in which consecutive positions the perforating tool 27 is operated, thereby making a nearly complete circle of holes through the wall of the casing 12, but the circle of perforations is discontinued before the casing seam is again reached so that all possibility of the perforating tool 27 being forced out through the casing seam is avoided. The perforator 11 may be then raised or lowered to another position, the separate steps of locating the seam, removing the perforator 27 from alignment with the seam, and operating the perforating tool 27 then being repeated to produce another circle of perforations.

Although I have herein shown and described a simple and operative form of my invention, it is recognized. that certain parts or elements thereof are representative of other parts, elements, or mechanisms which may be ISO employed in substantially the same way to accomplish substantially the same results; therefore, it is to be understood that the invention is not to be limited to the details disclosed but shall have the scope of the following claim.

I claim as my invention:

A perforator of the character described, including; a structure adapted to be inserted in a casing; a perforating tool carried by said structure; and a member yieldably supported on said structure for locating a seam in said casing, said member having the end thereof sloped off so as to form a shoulder at one side thereof adapted to engage a seam in said casing When moved in opposition to said seam.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 6th day of November, 1929.

ROSCOE MOSS. 

